Measuring apparatus and exposure apparatus having the same

ABSTRACT

A measuring apparatus for measuring an optical performance of an optical system under test that has a numerical aperture of more than 0.6 at a light exit side, said measuring apparatus includes a numerical aperture decreasing part for decreasing the numerical aperture of a light exited from the optical system under test to 0.6 or less, and a detector for detecting an interference fringes formed by the light that passes through the numerical aperture decreasing part.

This is a divisional of co-pending U.S. patent application Ser. No.11/276,164, filed Feb. 16, 2006.

BACKGROUND OF THE INVENTION

The present invention relates generally to a measurement for an opticalperformance of an optical system under test and more particularly to ameasuring apparatus that measures a wave front aberration of aprojection optical system that transfers a pattern of a reticle onto anobject, and an exposure apparatus having the same.

A projection exposure apparatus is used to transfer a pattern on areticle (or a mask) onto an object to be exposed in manufacturingdevices, such as semiconductor devices, e.g., an IC and a LSI, imagepick-up devices, such as a CCD, display devices, such as a liquidcrystal panel, and magnetic heads, in the photolithography process. Thisexposure apparatus is required to transfer the pattern on the reticleonto the object precisely at a predetermined magnification. For thispurpose, it is important to use a projection optical system having goodimaging performance and reduced aberration. In particular, due to therecent demands for finer processing to the semiconductor device, atransferred pattern is more sensitive to the aberration of the opticalsystem. Therefore, there is a demand to measure the optical performance,such as a wave front aberration, of the projection optical system withhigh precision.

A conventional method that actually exposes a reticle pattern onto awafer, and observes and inspects the resist image using a scanningelectron microscope (“SEM”) or another means has a problem in a longtime inspection due to the exposure and development, difficult SEMoperations, and bad inspection reproducibility due to errors caused byresist applications and developments. Accordingly, as a solution forthese problems, various measuring apparatuses have conventionally beenproposed, such as a point diffraction interferometer (“PDI”) that has apinhole used to form an ideal spherical wave, a shearing interferometer,such as a lateral shearing interferometer (“LSI”), or a Talbointerferometer that utilizes the shearing interferometer, and a linediffraction interferometer (“LDI”) that has a slit used to form an idealcylindrical wave or an ideal elliptical wave. See, for example, JapanesePatent Applications, Publication Nos. 57-64139, 2000-146705, and2000-97666.

Nevertheless, the conventional entire system that includes the measuringapparatus and exposure apparatus separately is large and structurallycomplex, causing the increased cost and the long measuring time.Accordingly, applicant has already proposed an exposure apparatusequipped with an interferometer in Japanese Patent Application,Publication No. 2005-156506.

However, a curved of the interference fringes and a pitch differenceincrease according to the demands for finer processing to the circuitpattern and higher a numerical aperture (“NA”) of the projection opticalsystem, and a shearing ratio (an amount corresponding to a shift amountbetween a 0^(th) order light and ±1^(st) order light) particularlychanges according to positions. Then, the inventor discovered that theabove interferometer cannot maintain the high precision measurement, ifthe NA of the projection optical system becomes a predetermined value ormore.

BRIEF SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a measuring apparatusthat can measure a wave front with high precision even if a NA of aprojection optical system becomes higher, and an exposure apparatushaving the same.

A measuring apparatus according to one aspect of the present inventionfor measuring an optical performance of an optical system under testthat has a numerical aperture of more than 0.6 at a light exit side,said measuring apparatus includes a numerical aperture decreasing partfor decreasing the numerical aperture of a light exited from the opticalsystem under test to 0.6 or less, and a detector for detecting aninterference fringes formed by the light that passes through thenumerical aperture decreasing part.

A measuring apparatus according to another aspect of the presentinvention for measuring an optical performance of an optical systemunder test that has a numerical aperture of more than 0.6 at a lightexit side, said measuring apparatus includes a substrate forinterference measurement that is used for the numerical aperture of 0.6or less of a light exited from the optical system under test, andincludes a first pattern that has a first pitch, and a second patternthat has a second pitch, the second pitch corresponding to the numericalaperture of more than 0.6 of the light exited from the optical systemunder test and being narrower than the first pitch, and a detector fordetecting an interference fringes formed by the light, wherein saidmeasuring apparatus combines results of plural measurements, using thefirst pattern and the second pattern.

An exposure apparatus according to another aspect of the presentinvention for exposing a pattern of a reticle onto an object via aprojection optical system using a light from the light source, saidexposure apparatus comprising a measuring apparatus for detecting anoptical performance of the projection optical system using the light asan interference fringes, wherein said projection optical system has anumerical aperture of more than 0.6 at an object side, and wherein saidmeasuring apparatus is the above measuring apparatus.

A device fabrication method according to another aspect of the presentinvention includes the steps of exposing an object using the aboveexposure apparatus, and performing a development process for the objectexposed.

Other objects and further features of the present invention will becomereadily apparent from the following description of the preferredembodiments with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram of an exposure apparatus as a firstembodiment according to the present invention.

FIG. 2 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a second embodiment according to the presentinvention.

FIG. 3 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a third embodiment according to the presentinvention.

FIG. 4 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a fourth embodiment according to the presentinvention.

FIG. 5 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a fifth embodiment according to the presentinvention.

FIG. 6 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a sixth embodiment according to the presentinvention.

FIG. 7 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a seventh embodiment according to thepresent invention.

FIG. 8 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as an eighth embodiment according to thepresent invention.

FIG. 9 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a ninth embodiment according to the presentinvention.

FIG. 10 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a tenth embodiment according to the presentinvention.

FIG. 11 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as an eleventh embodiment according to thepresent invention.

FIG. 12 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a twelfth embodiment according to thepresent invention.

FIG. 13 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a thirteenth embodiment according to thepresent invention.

FIG. 14 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a fourteenth embodiment according to thepresent invention.

FIG. 15 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a fifteenth embodiment according to thepresent invention.

FIG. 16 is a schematic block diagram of an exposure apparatus as asixteenth embodiment according to the present invention.

FIG. 17 is a plane view of a substrate for interference measurement atthe wafer side used for a measuring apparatus as a seventeenthembodiment according to the present invention.

FIG. 18 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as an eighteenth embodiment according to thepresent invention.

FIG. 19 is a schematic partially block diagram of a measuring apparatusof an exposure apparatus as a nineteenth embodiment according to thepresent invention.

FIG. 20 is a flowchart for explaining how to fabricate devices (such assemiconductor chips such as ICs, LCDs, CCDs, and the like)

FIG. 21 is a detail flowchart of a wafer process in Step 4 of FIG. 20.

FIG. 22 is a schematic block diagram of an exposure apparatus thatincludes a conventional interferometer.

FIG. 23 is a graph of a relationship of an optical path differencebetween a numerical aperture of a projection optical system and ±1^(st)order light.

FIGS. 24A and 24B are views for explaining problems of the conventionalinterferometer that receives a light having a higher numerical aperture.

FIG. 25 is a graph of a relationship of the numerical aperture of theprojection optical system and a shearing ratio.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

First, a description will be given of a relationship between ameasurement precision and a numerical aperture (NA) of a projectionoptical system. FIG. 22 is a block diagram of an exposure apparatus 10that includes an interferometer that measures an optical performance ofa projection optical system 15. A controller (not shown) drives areticle stage 14 and a wafer stage 18 and provides a reticle 13 and awafer 17 on an optical path at exposure. Then, a circuit pattern (notshown) on the reticle 13 is illuminated by an illumination opticalsystem 11 and printed on the wafer 17 through the projection opticalsystem 15. Usually, a NA of a light entering the projection opticalsystem 15 from the illumination optical system 11 is smaller than a NAof a light exiting from the projection optical system 15 for amagnification of the projection optical system 15. The present inventionpays attention to the NA of the light exited from the projection opticalsystem 15, and this defines as the NA of the projection optical systemin this application.

When the optical performance of the projection optical system 15 ismeasured, the controller drives the reticle stage 14 and the wafer stage18 and provides a substrate for interference measurement at the reticleside 12 and a substrate for interference measurement at the wafer side16 on the optical path. The substrate for interference measurement atthe reticle side 12 includes, for example, a pinhole 12 a, and thesubstrate for interference measurement at the wafer side 16 includes,for example, a grating 16 a.

The light passed through the illumination optical system and exited fromthe pinhole 12 a provided the substrate for interference measurement atthe reticle side 12 penetrates the projection optical system 15 andbecomes a light with an aberration information of the projection opticalsystem 15. The grating 16 a divides the light into each order componentand forms an interference fringes by overlapping them. Thereby, thisinterferometer is a LSI, and a light intensity sensor (CCD) measures theinterference fringes.

FIG. 23 shows a relationship of an optical path difference between theNA obtained by the exposure apparatus 10 and ±1^(st) order light. Datahas disappeared in ranges where NA exceeded 0.9. This is because the±1^(st) order light becomes an evanescent wave if NA is high, and doesnot exit from the grating. Although the optical path differencecertainly changes according to a pitch of the grating 16 a and aposition of the light intensity sensor 19, the optical path differenceis, as shown in FIG. 23, almost 0 in the range of NA to 0.5. However,the optical path difference rapidly increases when the NA exceeds 0.6.Because this optical path difference is measured as the interferencefringes, the rapidly increase of the optical path difference causes thefollowing problems.

One of the problems is a curvature of the interference fringes. Thelight intensity sensor 19 receives, as shown in FIG. 24A, a sphericalwave at a plane, and measures the interference fringes shown in FIG.24B. Then, a computing unit (or controller) of the interferometerimage-analyzes the obtained interference fringes, and calculates a wavefront aberration of the projection optical system 15. In order tomeasure the wave front aberration of the projection optical system 15with high precision, it is necessary to acquire the information of theinterference fringes from 0 to the maximum NA with respect to the NA ofthe projection optical system 15 (in other words, information of thewhole surface of the projection optical system 15) within the limit ofmeasurement accuracy of the light intensity sensor 19.

However, if the NA of the projection optical system 15 is higher, acurvature of the wave front becomes large, and the interference fringesgreatly curves in circumference of the interference fringes even if theaberration does not exist.

Another is a problem that the interference fringes covering the entiresurface of the projection optical system cannot be measured. The opticalpath is related to a pitch difference between the interference fringesof the center and the circumference. When the optical path difference inthe NA of 0.5 or less is 0, the interference fringes with the equalpitch are obtained in the entire NA of the projection optical system.However, when the optical path difference exists, the pitch differencebetween the interference fringes of the center and the circumference iscaused. Even if this pitch difference slightly exists, the interferencefringes in the entire NA of the projection optical system should bemeasured. However, when the NA exceeds 0.6, the optical path differencerapidly increases, and the pitch of the interference fringes of thecenter part shown in FIG. 24B becomes smaller than a pixel size of thelight intensity sensor 13.

Therefore, a spacing of the interference fringes is narrower for thelight intensity sensor 13, and plural interference fringes are detectedas one thick line. Actually, the light intensity sensor with 1 pixel toseveral pixels is needed to measure 1 interference fringe, and if thespacing of the interference fringes is narrower, information on the areais missing.

Then, when the light intensity sensor is adjusted so that the fineinterference fringes of the center part can be measured, theinterference fringes of which spacing is wide in circumference cannot bemeasured. Moreover, when the light intensity sensor is adjusted so thatthe interference fringes of which spacing is wide in circumference canbe measured, the fine interference fringes of the center part cannot bemeasured. Thereby, when the NA exceeds 0.6, the light intensity sensorcannot measure the interference fringes of the entire NA at once. Suchpitch difference of the interference fringes and increase of the curvedcause the precision deterioration of the image analysis and the longanalyzing time. Moreover, if the interference fringes covering theentire NA of the projection optical system cannot be measured at once,the image analysis cannot be executed, and the wave front cannot bemeasured. Therefore, when the NA exceeds 0.6, the optical performance ofthe projection optical system cannot be measured with high precision.

Moreover, in the LSI using the grating 12 a shown in FIG. 23, theshearing ratio (an amount corresponding to a shift amount between a0^(th) order light and ±1^(st) order light) differs at the center partand the circumference of the wave front by the increase of the NA. Inother words, the shearing ratio changes at the position. The shearingratio is a lateral shift amount of the wave front by the grating 16 a,when the NA is small, the lateral shift amount of the wave front isalmost constant, and simply, it can be considered that the wave frontshifts in the lateral direction. However, the lateral shift amountchanges in the position by the increase of the NA, the lateral shiftamount in a center of the light and an edge of the light differ, and thelateral shift amount increases as for the edge of the light. FIG. 25shows a relationship between the shearing ratio and the NA. When the NAis higher than 0.6, the shearing ratio of ±1^(st) order diffractionlight rapidly increases as shown in FIG. 25.

A description will be given of a measurement error and a reduction ofimage processing error by being the NA of the projection optical systemto 0.6 or less. As above-mentioned, if the NA is more than 0.6 and theoptical path difference increases, the interference fringes curve, andthe interference fringes covering the entire NA of the projectionoptical system cannot be measured. In this case, first, the interferencefringes of only the center part are measured, next, the circumferencepart is plurality measured for an area, which can be measured, and theinformation of the entire interference fringes is created bysynthesizing the plural images by the image processing. Thereby, errorfactors by the increase of the number of measurement and differing themeasurement conditions of each interference fringes increase, and theincrease of the image processing time and the precision deterioration ofthe plural image in a connection boundary.

Therefore, the good interference fringes of the entire NA of theprojection optical system can be obtained by decreasing the NA to 0.6 orless by a numerical aperture decreasing part, which is a characteristicof the present invention. Thereby, the number of measurement is becometo the minimum, the error factors by the measurement can be reduced, andthe image processing time and error factor can be reduced. As theresult, the present invention can measure the wave front with highprecision.

On the other hand, the measurement using the interferometer uses,usually, parallel light in many cases. However, when the NA of theprojection optical system increases, it is difficult to design acollimator lens for closing to the parallel light with a NA of 0.25 orless. The interferometer using the exposure light needs the shortestoptical path because a coherence of the exposure light is low, but thehigher NA of the projection optical system causes an increase in thenumber of collimator lenses, and the optical path length becomes longer.The increase of the number of lenses causes an enlargement of theinterferometer, especially, when the interferometer is mounted to theexposure apparatus, and a problem of arrangement occurs. Moreover, ifthe number of collimator lenses increases, an assembly error of thecollimator lenses increases, and the error factor not only increases,but a system error component for dividing the optical performance of theprojection optical system and the collimator lenses becomes complicated.In addition, the increase of the number of lenses decreases the lightintensity and the coherence, and the measurement with high precisioncannot be executed as a result.

Hereafter, with reference to the accompanying drawings, a descriptionwill be given of exposure apparatuses as various embodiments.

First Embodiment

FIG. 1 is a schematic block diagram of an exposure apparatus 100 as thefirst embodiment according to the present invention. The exposureapparatus 100 is a projection exposure apparatus to expose a circuitpattern of a reticle 120 onto an object (plate) 140, e.g., in astep-and-scan or a step-and-repeat manner. Such an exposure apparatus issuitably applicable to a submicron or quarter-micron lithographyprocess, and in the following embodiment, a step-and-scan exposureapparatus (which is also called “a scanner”) is described as an example.

The exposure apparatus 100 includes a measuring apparatus 200, anillumination apparatus, the reticle 120, a projection optical system130, and the plate 140.

The illumination apparatus illuminates the reticle 120 that has thecircuit pattern to be transferred, and includes a light source section(not shown) and an illumination optical system 110. The light sourcesection may use a light source such as an ArF excimer laser with awavelength of approximately 193 nm and a KrF excimer laser with awavelength of approximately 248 nm. A kind of laser is not limited toexcimer laser, and the number of laser units is not limited. Theillumination optical system 110 is an optical system that uniformlyilluminates the reticle 120, and includes a lens, a mirror, an opticalintegrator, a σ stop, and the like.

The reticle 120 is made, for example, of quartz, and has the circuitpattern (or an image) to be transferred. The reticle 120 is supportedand driven by a reticle stage 122. The reticle stage 122 has the samestructure as a wafer stage 142 described later, and supports and drivesa part of the measuring apparatus 200. The reticle stage 122 providesthe reticle 120 on the optical path at exposure, and provides asubstrate 130 on the optical path at measurement of the opticalperformance of the projection optical system 130. The diffracted lightfrom the reticle 120 passes the projection optical system 130, and thenis projected onto the plate 140. The mask 120 and the plate 140 arelocated in optically conjugate relationship. Since the exposureapparatus 100 is the scanner, the reticle 120 and the plate 140 arescanned at a speed ratio of the reduction ratio. Thus, the pattern ofthe reticle 120 is transferred to the plate 140. If the exposureapparatus 100 is a step-and-repeat exposure apparatus (referred to as a“stepper”), the reticle 120 and the plate 140 remains still whenexposing the reticle pattern.

The projection optical system 130 may use an optical system comprisingsolely of a plurality of lens elements, an optical system including aplurality of lens elements and at least one concave mirror (acatadioptric optical system), a full mirror type optical system, and soon. Any necessary correction of the chromatic aberration may beaccomplished by using a plurality of lens units made from glassmaterials having different dispersion values (Abbe values) or arranginga diffractive optical element such that it disperses light in adirection opposite to that of the lens unit. The projection opticalsystem 130 of the present invention has a NA of more than 0.6 at waferside.

The plate 140 is an exemplary object to be exposed, such as, a wafer anda LCD. A photoresist is applied to the plate 140. The plate 140 issupported by the wafer stage 142 via a chuck (not shown). The waferstage 142 supports the plate 140 and a part of the measuring apparatus200. The wafer stage 142 provides the plate 140 on the optical path atexposure, and provides a substrate 240 on the optical path atmeasurement of the optical performance of the projection optical system130. The wafer stage 142 may use any structures known in the art. Adetailed description of its structure and operation is omitted. Thewafer stage 142 may use, for example, a linear motor to move the plate140 and a part of the measuring apparatus 200. The reticle 120 and theplate 140 are, for example, scanned synchronously. The positions of thewafer stage 142 and reticle stage 122 are monitored, for example, by theinterferometer (not shown), so that both are driven at a constant speedratio.

The measuring apparatus 200 measures the optical performance (forexample, a wave front aberration) of the projection optical system 130using the exposure light or a light source for the interferometer. Themeasuring apparatus 200 includes a substrate (or mask) at the reticleside 210, a numerical aperture decreasing part 220, a substrate (ormask) at wafer side 240, an order selecting window 244, a detector 250,a controller 260, and a memory 262. The measuring apparatus 200 includesan interferometer that measures the optical performance of theprojection optical system 160 as the optical system under test bydetecting the interference fringes, and uses the LSI as theinterferometer. However, the measuring apparatus 200 may use the PDI orLDI as described later.

The substrate 210 is a pinhole board, and is provided on a predeterminedobject point in an object surface position of the projection opticalsystem 130. The substrate 210 includes a pinhole 212 to form a sphericalwave of a measurement light.

The numerical aperture decreasing part 220 decreases a numericalaperture of a light exited from the projection optical system 130 to 0.6or less. The numerical aperture decreasing part 220 of the instantembodiment is a concave lens provided before an imaging point (focalpoint) on the plate at exposure. The number of lenses included thenumerical aperture decreasing part 220 is not limited to 1. Thenumerical aperture decreasing part 220 may be a lens unit that includesplural lenses having a negative power.

The numerical aperture decreasing part 220 does not need to generate acompletely parallel light and may narrow so that the light entered thesubstrate for interference measurement or the light entered the lightintensity sensor becomes a light with a NA of 0.25 or more and 0.6 orless. If the NA is 0.6 or less, the measurement precision can be withintolerance. If the NA is 0.25 or more, the increase of the optical pathlength by introducing the collimator lens unit can be reduced. Thecollimator that controls the numerical aperture of the projectionoptical system so that the NA becomes 0.25 or more and 0.6 or less is asimply structure, can set a coherence distance and the light intensityin tolerance, and can maintain a predetermined measurement precision.

The numerical aperture decreasing part 220 is not limited to the concavemirror. The numerical aperture decreasing part 220 may use a diffractiveoptical element, such as a binary optics, a Fresnel zone plate, and aFresnel lens.

The substrate 240 includes a grating pattern 242 at the projectionoptical system side, and coupled with the order selecting window 246 atthe plate side via a connecting part 224. As the result, the substrate240 and the order selecting window 246 drive together.

The substrate 210 may use a slit or a grating, and the substrate 240 mayuse a double slit or a structure that includes a slit and a window. Thegrating may use an amplitude grating constituted by providing alight-shielding part, such as Cr, in a glass substrate, and a phasegrating that has a phase difference by an incision of the glass. Whenthe grating is used, two 1^(st) order gratings in X and Y directions maybe used, and a 2^(nd) order grating that has a hounds-tooth check shapemay be used. Moreover, an image shifted the phase can be obtained bymoving only grating in an orthogonal direction to the optical axis usingthe stage, and a phase information of the projection optical system maybe obtained from these plural image.

The order selecting window 244 is provided the imaging point at theplate 140 side, and cuts unnecessary light, such as high order lightgenerated in the grating 242. The order selecting window 244 includes,for example, a couple of square window 247 a that aligners in the Xdirection and is same shape, and a couple of square window 247 b thataligners in the Y direction and is same shape. The window 247 a and thewindow 247 b exists on same the order selecting window 244, and canadjust a distance between the patterns with an electron beam formingprecision (almost 50 nm) manufactured the order selecting window 244.The position of the order selecting window 244 is adjusted so that theimage (0^(th) order light) is formed at the center of the two windows247 a for the shearing measurement in the X direction. The substrate 240that includes the 2^(nd) order grating 242 is designed and provided sothat the ±1^(st) order light passes the center of the two windows 247 a.The shearing ratio of the ±1^(st) order light is determined based on aninterval of window 247 a, a distance between the grating 242 and theorder selecting window 244, a spacial frequency needed for a wave frontreconstruction, and a contrast needed for the interference fringes, etc.Moreover, the order selecting window 244 is aligned so that the image(0^(th) order light) is formed at the center of the two windows for theshearing measurement in the Y direction As the result, the XY componentcan be measured at the same time. Of course, the present invention maytime-serially take in the XY component by dividing the window 247 a andthe window 247 b in the X direction.

The detector 250 is a detector, such as back-irradiating type CCD, acamera, and other interference fringes pick-up image means. Thecontroller 260 controls the reticle stage 122 and the wafer stage 142,analyzes the wave front by obtaining the shearing interferenceinformation detected by the detector 250, and calculates the wave frontaberration of the projection optical system 130. The memory 262 storesinformation and result needed for the control and calculation by thecontroller 260.

In operation of the measuring apparatus 200, the light exited from thepinhole 212 of the structure 210 becomes a light having the aberrationinformation of the projection optical system 130 by passing though theprojection optical system 130. This light is narrowed by the numericalaperture decreasing part 220, passes through the grating pattern 242,and images on the order selecting window 244. The grating 142 dividesthe light into each order component, and the order selecting window 246remove the 0^(th) order light and high order diffraction light. As theresult, only ±1^(st) order light penetrates the window 247 a and thewindow 247 b, and they form the interference fringes by overlapping. Thedetector 250 detects the interference fringes.

The controller 260 calculates the wave front from the interferencefringes, and obtains the optical information of the projection opticalsystem.

Concretely, the detector 250 measures the interference fringes formed bythe ±1^(st) order light penetrated the window 247 a and the window 247b. The instant embodiment uses a Fourier transform method to obtain thephase (wave front) information from the interference fringes.

First, the Fourier transform method 2^(nd) order Fourier-transforms theinterference fringes. In the spacial frequency, an interference spectrumcorresponding to each shearing wave front in the X direction and the Ydirection. Two of the differential wave in the X direction and the wavefront difference in the Y direction are obtained by an inverse Fouriertransform of the frequency distribution. Since these phase informationis a discrete information for 360 degree, these phase information isphase-connected (unwrap) so that the phase smoothly connect.

There are various techniques for obtaining the phase information fromthe interference fringes beside the above Fourier transform method.

One is an electron moiré method. This method observes the interferencefringes image included a carrier fringes by the image pick-up means. Onthe other hand, a computer generates three or more reference gratingpattern signals that have the same frequency as the interference fringesimage and shifts the phase of a predetermined amount, and multiples ameasurement interference fringes signal respectively. The phasedistribution is obtained from three or more moiré interference fringesimage obtained by extracting the low frequency component from the signalobtained by the multiplication.

There is a phase shift method for the higher precision. This methoddrives the grating in the orthogonal direction to the optical axis, andcalculates the differential phase information from plural image shiftedthe phase. First, the grating is driven in the X direction, and thedifferential wave in the X direction is calculated from the plural imageshifted the phase. Also, the grating is driven in the Y direction, andthe differential wave in the Y direction is calculated from the pluralimage shifted the phase. It is the same structure even if it uses twoline gratings in the X direction and the Y direction.

The instant embodiment is the shearing interferometer using the grating,and calculates the wave front difference. Therefore, the original wavefront (in other words, the optical information of the projection opticalsystem) can be obtained by integrating with such differential wave.

As above-mentioned, the differential wave in the X direction and thedifferential wave in the Y direction can be obtained from variousmethods. Therefore, the optical information of the projection opticalsystem can be obtained by synthesizing and integrating these twodifferential waves.

It is necessary to separate the optical property (system error) of thenumerical aperture decreasing part 220 from the detection result by thedetector 250 to measure the optical property of the projection opticalsystem 130 with high precision. The system error may measure the opticalproperty of the numerical aperture decreasing part 220 and stores it inthe memory 262. Moreover, the projection optical system 130 is measuredby another higher performance measuring apparatus, and the differentialmay be the system error.

Second Embodiment

Referring to FIG. 2, a description will be given of an exposureapparatus 100A as the second embodiment according to the presentinvention. Here, FIG. 2 is a schematic block diagram of a measuringapparatus 200A after the projection optical system 130 of the exposureapparatus 100A. In FIG. 2, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted. The exposureapparatus 100A is different form the exposure apparatus 100 in that theexposure apparatus 100A has a substrate for interference measurement atthe wafer side 240A instead of the members 240 to 246. The substrate240A includes the grating pattern 242 at the surface, and an orderselecting window 246A that cuts the higher order light at the backsurface. The exposure apparatus 100A can be miniaturized, can simplifystructure, and can shorten distance between the grating 242 and theorder selecting window 246A, as compared with the exposure apparatus 100

Third Embodiment

Referring to FIG. 3, a description will be given of an exposureapparatus 100B as the third embodiment according to the presentinvention. Here, FIG. 3 is a schematic block diagram of a measuringapparatus 200B after the projection optical system 130 of the exposureapparatus 100B. In FIG. 3, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted. Themeasuring apparatus 200B is different form the measuring apparatus 200in that a convex lens 220B as the numerical aperture decreasing part isprovided after the focal point of the projection optical system 130. Thenumerical aperture decreasing part 220B decreases the NA of theprojection optical system 130 so that the NA of the light penetrated theprojection optical system 130 becomes 0.6 or less (for example, 0.25 ormore and 0.6 or less). The operation of the measuring apparatus 200B isthe same as the measuring apparatus 200. The NA of the light entered thedetector 250 is smaller than the NA of the projection optical system 130by the numerical aperture decreasing part 220B. The good interferencefringes in the entire surface of the projection optical system areobtained because the NA of the light entered the detector 250 becomes0.6 or less, and the measuring apparatus 200B can measure with highprecision.

Fourth Embodiment

Referring to FIG. 4, a description will be given of an exposureapparatus 100C as the fourth embodiment according to the presentinvention. Here, FIG. 4 is a schematic block diagram of a measuringapparatus 200C after the projection optical system 130 of the exposureapparatus 100C. In FIG. 4, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted. Themeasuring apparatus 200C is different from the measuring apparatus 200in that a hemispheric lens 220C as the numerical aperture decreasingpart is provided between the back surface of the substrate 240 and thedetector 250. The numerical aperture decreasing part 220C decreases theNA of the projection optical system 130 so that the NA of the lightpenetrated the projection optical system 130 becomes 0.6 or less (forexample, 0.25 or more and 0.6 or less). The measuring apparatus 200Cprovides the hemispheric lens 220C and the substrate 240 in a directionthat a plane part of the hemispheric lens 220C and the back surface ofthe substrate 240 are united. The operation of the measuring apparatus200C is the same as the measuring apparatus 200. The NA of the lightentered the detector 250 is smaller than the NA of the projectionoptical system 130 by the numerical aperture decreasing part 220C. Thegood interference fringes in the entire surface of the projectionoptical system are obtained because the NA of the light entered thedetector 250 becomes 0.6 or less, and the measuring apparatus 200C canmeasure with high precision.

Fifth Embodiment

Referring to FIG. 5, a description will be given of an exposureapparatus 100D as the fifth embodiment according to the presentinvention. Here, FIG. 5 is a schematic block diagram of a measuringapparatus 200D after the projection optical system 130 of the exposureapparatus 100D. In FIG. 5, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted. Themeasuring apparatus 200D is different form the measuring apparatus 200Cin that the back surface of the substrate 240 optical-contacts the planepart of the hemispheric lens 220C. The operation of the measuringapparatus 200D is the same as the measuring apparatus 200C. The NA ofthe light entered the detector 250 is smaller than the NA of theprojection optical system 130 by the numerical aperture decreasing part220C. The good interference fringes in the entire surface of theprojection optical system are obtained because the NA of the lightentered the detector 250 becomes 0.6 or less, and the measuringapparatus 200D can measure with high precision.

Sixth Embodiment

Referring to FIG. 6, a description will be given of an exposureapparatus 100E as the sixth embodiment according the present invention.Here, FIG. 6 is a schematic block diagram of a measuring apparatus 200Eafter the projection optical system 130 of the exposure apparatus 100E.In FIG. 6, the same reference numeral denotes the same element.Therefore, duplicate descriptions will be omitted. The measuringapparatus 200E is different from the measuring apparatus 200D in thatthe measuring apparatus 200E uses a substrate 240E that has a curvature(convex) at the back surface. The operation of the measuring apparatus200E is the same as the measuring apparatus 200D. The NA of the lightentered the detector 250 is smaller than the NA of the projectionoptical system 130 by the substrate 240E having the function of thenumerical aperture decreasing part. The good interference fringes in theentire surface of the projection optical system are obtained because theNA of the light entered the detector 250 becomes 0.6 or less, and themeasuring apparatus 200E can measure with high precision.

Seventh Embodiment

Referring to FIG. 7, a description will be given of an exposureapparatus 100F as the seventh embodiment according the presentinvention. Here, FIG. 7 is a schematic block diagram of a measuringapparatus 200F after the projection optical system 130 of the exposureapparatus 100F. In FIG. 7, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted.

The measuring apparatus 200F is different from the measuring apparatus200 in that the measuring apparatus 200F fills between the projectionoptical system 130 and the detector 250 with a liquid as numericalaperture decreasing part 220 that penetrates the exposure apparatus andhas a refractive index of 1 or more. Between the projection opticalsystem 130 and the detector 250 is between the projection optical system150 and the substrate 240, and between the substrate 240 and thedetector 250. The liquid may use a pure water that has a refractiveindex of 1.44 and other liquid. The operation of the measuring apparatus200F is the same as the measuring apparatus 200. The NA of the lightentered the detector 250 is smaller than the NA of the projectionoptical system 130 by the numerical aperture decreasing part 220. Thegood interference fringes in the entire surface of the projectionoptical system are obtained because the NA of the light entered thedetector 250 becomes 0.6 or less, and the measuring apparatus 200F canmeasure with high precision. In the instant embodiment, the liquid isfilled a space between the projection optical system 130 and thesubstrate 240 and a space between the substrate 240 and the detector250. However, a different kind liquid may fill both spaces. This is thesame as the following embodiment.

Eighth Embodiment

Referring to FIG. 8, a description will be given of an exposureapparatus 100G as the eighth embodiment according the present invention.Here, FIG. 8 is a schematic block diagram of a measuring apparatus 200Gafter the projection optical system 130 of the exposure apparatus 100G.In FIG. 8, the same reference numeral denotes the same element.Therefore, duplicate descriptions will be omitted. Since the measuringapparatus 200G provides the last surface of the projection opticalsystem 130 in air, can be applied to an exposure apparatus that is notthe immersion exposure apparatus. The measuring apparatus 200G is filledwith the liquid at only interference measurement, and a flexibility ishigh. The measuring apparatus 200G is different from the measuringapparatus 200 in that the final lens surface of the projection opticalsystem 130 does not contact the liquid, and the liquid is filled from amiddle between the projection optical system 130 and the substrate 240,as the numerical aperture decreasing part 220. The refractive indexdifference between the liquid and air decreases the NA. The operation ofthe measuring apparatus 200G is the same as the measuring apparatus200F. The NA of the light entered the detector 250 is smaller than theNA of the projection optical system 130 by the numerical aperturedecreasing part 220. The good interference fringes in the entire surfaceof the projection optical system are obtained because the NA of thelight entered the detector 250 becomes 0.6 or less, and the measuringapparatus 200G can measure with high precision.

Ninth Embodiment

Referring to FIG. 9, a description will be given of an exposureapparatus 100H as the ninth embodiment according the present invention.Here, FIG. 9 is a schematic block diagram of a measuring apparatus 200Hafter the projection optical system 130 of the exposure apparatus 100H.In FIG. 9, the same reference numeral denotes the same element.Therefore, duplicate descriptions will be omitted. The measuringapparatus 200H is different from the measuring apparatus 200G in that asubstrate for interference measurement at the wafer side 240H has apattern, such as pinhole and a window or a slit and a window, and servesas the PDI or the LDI. It is same to decrease the numerical aperture bythe refractive index difference between the liquid and air.

In the operation of the measuring apparatus 200H, the ideal wave existsfrom the pinhole or slit, the wave included the optical information ofthe projection optical system 130 from the window, and detector 250measures interference fringes of these waves. The NA of the lightentered the detector 250 is smaller than the NA of the projectionoptical system 130 by the numerical aperture decreasing part 220. Thegood interference fringes in the entire surface of the projectionoptical system are obtained because the NA of the light entered thedetector 250 becomes 0.6 or less, and the PDI and LDI can measure withhigh precision.

Tenth Embodiment

Referring to FIG. 10, a description will be given of an exposureapparatus 100I as the tenth embodiment according the present invention.Here, FIG. 10 is a schematic block diagram of a measuring apparatus 200Iafter the projection optical system 130 of the exposure apparatus 100I.In FIG. 10, the same reference numeral denotes the same element.Therefore, duplicate descriptions will be omitted. The measuringapparatus 200I is different from the measuring apparatus 200G in that aconcave lens 220 is provided a boundary between the liquid and air whenthe liquid is filled between the projection optical system 130 and thesubstrate 240. In other words, the measuring apparatus 200I use two kindnumerical aperture decreasing parts 220 and 230. The concave lens 220 isprovided before the imaging point of the projection optical system 130,and the liquid 230 that penetrates the exposure light and has arefractive index of 1 or more is filled between the projection opticalsystem 130 and the substrate 240. The measuring apparatus 100I seals theliquid 230 by the concave lens 220. The operation of the measuringapparatus 100I is the same as the measuring apparatus 200G. The NA ofthe light entered the detector 250 is smaller than the NA of theprojection optical system 130 by the numerical aperture decreasing parts220 and 230. The good interference fringes in the entire surface of theprojection optical system are obtained because the NA of the lightentered the detector 250 becomes 0.6 or less, and the measuringapparatus 200I can measure with high precision.

Eleventh Embodiment

Referring to FIG. 11, a description will be given of an exposureapparatus 100J as the eleventh embodiment according the presentinvention. Here, FIG. 11 is a schematic block diagram of a measuringapparatus 200J after the projection optical system 130 of the exposureapparatus 100J. In FIG. 11, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted. Themeasuring apparatus 200J is different from the measuring apparatus 2001in that a convex lens 220C is provided the boundary between the liquidand air when the liquid is filled between the projection optical system130 and the substrate 240. In other words, the measuring apparatus 200Juses two kinds of numerical aperture decreasing parts 220C and 230. Theconvex lens 230C is provided after the imaging point of the projectionoptical system 130, and the liquid 230 that penetrates the exposurelight and has a refractive index of 1 or more is filled between theprojection optical system 130 and the substrate 240. The measuringapparatus 2001 seals the liquid 230 by the convex lens 220C. Theoperation of the measuring apparatus 200J is the same as the measuringapparatus 2001. The NA of the light entered the detector 250 is smallerthan the NA of the projection optical system 130 by the numericalaperture decreasing parts 220C and 230. The good interference fringes inthe entire surface of the projection optical system are obtained becausethe NA of the light entered the detector 250 becomes 0.6 or less, andthe measuring apparatus 200J can measure with high precision. FIG. 11shows the convex lens as hemispherical shape, and a convex lens that hasa power at both surfaces may be used.

Twelfth Embodiment

Referring to FIG. 12, a description will be given of an exposureapparatus 100K as the twelfth embodiment according the presentinvention. Here, FIG. 12 is a schematic block diagram of a measuringapparatus 200K after the projection optical system 130 of the exposureapparatus 100K. In FIG. 12, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted. Themeasuring apparatus 200K is different from the measuring apparatus 200Jin that the grating 242 is patterned on a back surface of a substrate240K, the convex lens 220C optical-contacts a surface of the substrate240K. A little distance between the convex lens 220C and the surface ofthe substrate 240K exists and the liquid may be filled between theconvex lens 220C and the surface of the substrate 240K, and the surfaceof the substrate 240K may have a curvature and the grating 242 may bepatterned on the back surface. These structures can be obtained the sameeffects. The operation of the measuring apparatus 200K is the same asthe measuring apparatus 200J. The NA of the light entered the detector250 is smaller than the NA of the projection optical system 130 by thenumerical aperture decreasing parts 220C and 230. The good interferencefringes in the entire surface of the projection optical system areobtained because the NA of the light entered the detector 250 becomes0.6 or less, and the measuring apparatus 200K can measure with highprecision.

Thirteenth Embodiment

Referring to FIG. 13, a description will be given of an exposureapparatus 100L as the thirteenth embodiment according the presentinvention. Here, FIG. 13 is a schematic block diagram of a measuringapparatus 200L after the projection optical system 130 of the exposureapparatus 100L. In FIG. 13, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted. Themeasuring apparatus 200L is different from the measuring apparatus 200Gin that the substrate for interference measurement at the wafer side 240seals the liquid 230. The grating 242 may be patterned the back surfaceof the substrate 240. The operation of the measuring apparatus 200L isthe same as the measuring apparatus 200G. The NA of the light enteredthe detector 250 is smaller than the NA of the projection optical system130 by the numerical aperture decreasing part 230. The good interferencefringes in the entire surface of the projection optical system areobtained because the NA of the light entered the detector 250 becomes0.6 or less, and the measuring apparatus 200L can measure with highprecision.

Fourteenth Embodiment

Referring to FIG. 14, a description will be given of an exposureapparatus 100M as the fourteenth embodiment according the presentinvention. Here, FIG. 14 is a schematic block diagram of a measuringapparatus 200M after the projection optical system 130 of the exposureapparatus 100M. In FIG. 14, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted. Themeasuring apparatus 200M is different from the measuring apparatus 200Jin that the measuring apparatus 200M has a convex lens 220M at after theback surface of the substrate 240. The operation of the measuringapparatus 200M is the same as the measuring apparatus 200J. The NA ofthe light entered the detector 250 is smaller than the NA of theprojection optical system 130 by the numerical aperture decreasing parts220C, 220M and 230. The good interference fringes in the entire surfaceof the projection optical system are obtained because the NA of thelight entered the detector 250 becomes 0.6 or less, and the measuringapparatus 200M can measure with high precision.

Fifteenth Embodiment

Referring to FIG. 15, a description will be given of an exposureapparatus 100N as the fifteenth embodiment according the presentinvention. Here, FIG. 15 is a schematic block diagram of a measuringapparatus 200N after the projection optical system 130 of the exposureapparatus 100N. In FIG. 15, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted. Themeasuring apparatus 200N is different from the measuring apparatus 200Ein that a substrate 240N adheres the detector 250. The operation of themeasuring apparatus 200N is the same as the measuring apparatus 200E. Inother words, the light penetrated the projection optical system 130 isdivided into each order component by the grating 242. The divided lightdirectly enters the detector 250 without penetrating air by adhering thesubstrate 240N and the detector 250. The NA entered the detector 250changes according to the refractive index of the substrate 240N, and theinstant embodiment sets the NA to 0.25 or more and 0.6 or less. The NAof the light entered the detector 250 is smaller than the NA of theprojection optical system 130 by the substrate 240N as the numericalaperture decreasing part. The good interference fringes in the entiresurface of the projection optical system are obtained because the NA ofthe light entered the detector 250 becomes 0.6 or less, and themeasuring apparatus 200N can measure with high precision.

Sixteenth Embodiment

Referring to FIG. 16, a description will be given of an exposureapparatus 100O as the sixteenth embodiment according the presentinvention. Here, FIG. 16 is a schematic block diagram of the exposureapparatus 100O. The exposure apparatus 100O uses a substrate forinterference measurement at the reticle side 2100 the same structure asthe substrate for interference measurement at the wafer side 240, andprovides the grating 214 at a position of conjugate. Moreover, theexposure apparatus 100O provides the numerical aperture decreasing part(concave lens) 220 between the projection optical system 130 and thesubstrate 240 similar to the exposure apparatus 100. The gratings 214and 242 have the same pitch in consideration of the magnification of theprojection optical system 130 and the numerical aperture decreasing part220.

The light passed through the illumination optical system 110 and dividedinto each order component by the grating 214 of the substrate 2100penetrates the projection optical system 130, and becomes a light thatincludes the aberration information of the projection optical system130. The light included the aberration information is narrowed by thenumerical aperture decreasing part 220, and is divided into each ordercomponent by the grating 242 of the substrate 240. The detector 250detects those interference fringes.

Here, the gratings 214 and 242 are provided the position of conjugate,and have the same pitch in consideration of the magnification of theprojection optical system 130 and the numerical aperture decreasing part220. Thereby, the light divided by the substrate 2100 is reconstructedby the substrate 240, and interference fringes of a one color withouttilt fringe can be obtained.

The measuring apparatus 200O provides the concave lens 220 before theimaging point of the projection optical system 130, and may provide aconvex lens 220B after the imaging point.

The NA of the light entered the detector 250 is smaller than the NA ofthe projection optical system 130 by the numerical aperture decreasingpart 220. The good interference fringes in the entire surface of theprojection optical system are obtained because the NA of the lightentered the detector 250 becomes 0.6 or less, and the exposure apparatus200O can measure with high precision.

Seventeenth Embodiment

Referring to FIGS. 17 and 23, a description will be given of theseventeenth embodiment according the present invention. Here, FIG. 17 isa plane view of three kind grating patterns 242P₁ to 242P₃ formed on asubstrate for interference measurement at the wafer side 16 a of theconventional exposure apparatus 10. The instant embodiment can improvethe measurement precision even if the conventional exposure apparatus isused.

When the NA is high, the curvature of the wave is large, and measurableinterference fringes cannot be obtained in the entire surface of theprojection optical system 15. For example, when the interference fringesof the center part can be measured, the interference fringes ofcircumference become dense and cannot be measured. The measuringapparatus selects a pattern for the NA, measures the measurable area byeach pattern, and obtains the optical property of the entire projectionoptical system 15 by uniting these results.

The optical path difference is small until the NA of 0.6 as shown inFIG. 23. Thereby, the measuring apparatus measures waves that have theNA of 0.6 or less using one pattern, and measures waves that have the NAof more than 0.6 using one or more pattern according the tilt of thewave. Then, the entire wave is formed by uniting those waves.

Concretely, in the measuring apparatus, the pattern 242P₁ calculates thewaves that have the NA of 0.6 or less, the pattern 242P₂ calculates thewaves that have the NA of 0.5 to 0.75, and the pattern 242P₃ calculatesthe waves that have the NA of 0.65 to 0.85. Then, the wave that has theNA of 0.85 is obtained by uniting them. Thereby, the measuring apparatususes a finer pitch pattern as the higher NA.

Eighteenth Embodiment

Referring to FIG. 18, a description will be given of an exposureapparatus 100P as the eighteenth embodiment according the presentinvention. Here, FIG. 18 is a schematic block diagram of a measuringapparatus 200P after the projection optical system 130 of the exposureapparatus 100P. In FIG. 18, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted. Themeasuring apparatus 200P is different form the measuring apparatus 200Kin that a plane concave lens 220P optical-contacts the substrate 240K. Alittle distance between the plane concave lens 220P and the surface ofthe substrate 240K exists and the liquid may be filled between the planeconcave lens 220P and the surface of the substrate 240K, and the surfaceof the substrate 240K may have a curvature and the grating 242 may bepatterned on the back surface. These structures can be obtained the sameeffects. The operation of the measuring apparatus 200P is the same asthe measuring apparatus 200K. The NA of the light entered the detector250 is smaller than the NA of the projection optical system 130 by thenumerical aperture decreasing parts 220P and 230. The good interferencefringes in the entire surface of the projection optical system areobtained because the NA of the light entered the detector 250 becomes0.6 or less, and the measuring apparatus 200P can measure with highprecision.

Nineteenth Embodiment

Referring to FIG. 19, a description will be given of an exposureapparatus 100Q as the eighteenth embodiment according the presentinvention. Here, FIG. 19 is a schematic block diagram of a measuringapparatus 200Q after the projection optical system 130 of the exposureapparatus 100Q. In FIG. 19, the same reference numeral denotes the sameelement. Therefore, duplicate descriptions will be omitted. Themeasuring apparatus 200Q is different from the measuring apparatus 200Bin that the measuring apparatus 200Q has a collimator lens 220Q as thenumerical aperture decreasing part. Therefore, the present inventiondoes not except that the numerical aperture decreasing part decreasesthe NA to 0.25 or less (for example, NA=0). The NA of the light enteredthe detector 250 is smaller than the NA of the projection optical system130 by the numerical aperture decreasing part 220Q. The goodinterference fringes in the entire surface of the projection opticalsystem are obtained because the NA of the light entered the detector 250becomes 0.6 or less, and the measuring apparatus 200P can measure withhigh precision.

Hereafter, a description will be given of an aberration correctionmethod according to one embodiment of the present invention. Theexposure apparatuses 100 to 100Q allow plural optical elements (notshown) in the projection optical system 130 to move in the optical axisdirection and/or a direction orthogonal to the optical axis direction.By driving one or more optical elements using a driving system (notshown) for aberration adjustments based on aberrational informationobtained from the instant embodiment, it is possible to correct oroptimize one or more aberrations of the projection optical system 130,in particular Zeidel's classification of aberrations. The means foradjusting the aberration of the projection optical system 130 can usevarious known systems, such as a movable lens, a movable mirror (whenthe projection optical system is a catadioptric optical system orfull-mirror optical system), an inclinable parallel plate, apressure-controllable space, and a surface correction using actuator.

In the normal exposure, the light exited from the light source sectionenters the illumination optical system 110. The light entered theillumination optical system 110 Koehler-illuminates, for example, thereticle 120. The reticle 120 is mounted on the reticle stage 122, anddriven during exposure in the scanner. The light that passes the reticle120 and reflects the reticle pattern is imaged onto the plate 140 fixedonto the wafer stage 142 via the wafer chuck (not shown) by theprojection optical system 130 at a projection magnification (forexample, ¼ and ⅕). The wafer chuck is provided on the wafer stage 142,and driven during the exposure. Since the aberration of the projectionoptical system 130 is corrected, the plate 140 can receive thehigh-quality exposure process (or the predetermined resolution).

Referring now to FIGS. 20 and 21, a description will be given of anembodiment of a device fabrication method using the above mentionedexposure apparatus 100 etc. FIG. 20 is a flowchart for explaining how tofabricate devices (i.e., semiconductor chips such as IC and LSI, LCDs,CCDS, and the like). Here, a description will be given of thefabrication of a semiconductor chip as an example. Step 1 (circuitdesign) designs a semiconductor device circuit. Step 2 (maskfabrication) forms a mask having a designed circuit pattern. Step 3(wafer preparation) manufactures a wafer using materials such assilicon. Step 4 (wafer process), which is also referred to as apretreatment, forms the actual circuitry on the wafer throughlithography using the mask and wafer. Step 5 (assembly), which is alsoreferred to as a post-treatment, forms into a semiconductor chip thewafer formed in Step 4 and includes an assembly step (e.g., dicing,bonding), a packaging step (chip sealing), and the like. Step 6(inspection) performs various tests on the semiconductor device made inStep 5, such as a validity test and a durability test. Through thesesteps, a semiconductor device is finished and shipped (Step 7).

FIG. 21 is a detailed flowchart of the wafer process in Step 4. Step 11(oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms aninsulating layer on the wafer's surface. Step 13 (electrode formation)forms electrodes on the wafer by vapor disposition and the like. Step 14(ion implantation) implants ions into the wafer. Step 15 (resistprocess) applies a photosensitive material onto the wafer. Step 16(exposure) uses the exposure apparatus 100 to expose a circuit patternfrom the mask onto the wafer. Step 17 (development) develops the exposedwafer. Step 18 (etching) etches parts other than a developed resistimage. Step 19 (resist stripping) removes unused resist after etching.These steps are repeated to form multi-layer circuit patterns on thewafer. The fabrication method of the instant embodiment can quickly andeasily obtain the imaging performance of the projection optical system130 whose wave front aberration has been highly precisely corrected canprovide an alignment for the wafer stage with high precision. Therefore,the manufacture semiconductor devices with good productivity andeconomical efficiency (such as semiconductor devices, LCD device, imagepickup device (e.g., CCDs), and thin film magnetic heads) which havebeen difficult to manufacture. Thus, the device fabrication method usingthe exposure apparatus 100, and resultant devices constitute one aspectof the present invention.

Furthermore, the present invention is not limited to these preferredembodiments and various variations and modifications may be made withoutdeparting from the scope of the present invention.

This application claims a foreign priority benefit based on JapanesePatent Applications No. 2005-040271, filed on Feb. 17, 2005, which ishereby incorporated by reference herein in its entirety as if fully setforth herein.

1. A measuring apparatus for measuring an optical performance of anoptical system to be measured that has a numerical aperture of more than0.6 at a light exit side, said measuring apparatus comprising: asubstrate for interference measurement that includes a first patternthat has a first pitch, and a second pattern that has a second pitch,the first pitch being used for the numerical aperture of 0.6 or less ofa light exited from the optical system, the second pitch being used forthe numerical aperture of more than 0.6 of the light exited from theoptical system and being narrower than the first pitch; and a detectorfor detecting interference fringes formed by the light, wherein saidmeasuring apparatus combines results of plural measurements using thefirst pattern and the second pattern.
 2. An exposure apparatus forexposing a pattern of a reticle onto an object via a projection opticalsystem using a light from the light source, said exposure apparatuscomprising a measuring apparatus for detecting an optical performance ofthe projection optical system using the light as interference fringes,wherein said projection optical system has a numerical aperture of morethan 0.6 at an object side, and wherein said measuring apparatus is ameasuring apparatus according to claim
 1. 3. A device fabrication methodcomprising the steps of: exposing an object using an exposure apparatusaccording to claim 2; and performing a development process for theobject exposed.
 4. A measuring apparatus to claim 1, wherein the firstpattern and the second pattern include: a pattern used for the numericalaperture of 0.6 or less of the light exited from the optical system, apattern used for the numerical aperture from 0.5 to 0.75 of the lightexited from the optical system, and a pattern used for the numericalaperture from 0.65 to 0.85 of the light exited from the optical system.